//1、导包
const mongoose = require('mongoose');
//2、连接数据库
mongoose.connect("mongodb://127.0.0.1:27017/books");
//3、设置回调函数，用来检测数据库连接成功与否
mongoose.connection.on('open', () => {
    console.log('数据库连接成功');
})
mongoose.connection.on('error', () => {
    console.log('数据库连接失败');
})
module.exports = mongoose;